Vaillant Ecotec 630 plus pump trouble

[jdsmith]

I have a 630 plus with a very noisy pump which occasionally gets "stuck" and gives F.75 error. Usually can get it going again with a gentle tap to the pump body and/or persistent reset button presses until it starts but it is annyoing. I have been led to believe this is likely to be due to sludge in the system.
I bought a replacement (new) pump on ebay which has the correct Vaillant part number but looks slightly different - mine has a black label, the new one has a silver label and the rounded arrow printed under the pump bleed screw points in the opposite direction. (One is labelled VPAR... and the other VPAL...). The connections look the same.

I have a few questions I hope someone could help answer.
Does the printed arrow indicate direction of rotation of the impeller? And does the fact that this appears to be going the other way round from the current pump cause a problem?
More specifically, I was hoping to just swap the pump heads over - am I going to be able to do this?

 

[gas4you]

New Vaillant pumps are Grunfoss, whilst the old ones are Wilo, so no, you cannot just change the heads over, you need to change the pump and block as a whole.

 

[lightning]

Don't think you can buy the wilo's anymore as said need to change the whole pump

 

[jdsmith]

Is changing the pump likely to be "difficult"? - it looks more fiddly than difficult but are there any troublesome aspects to it? I've changed separate pumps before but never one that is integrated into a boiler.

Jason

 

[Agile]

That all depends on your perception of difficult.

I do boiler repairs and it does not phase me to have to change one of those.

But I dont look forward to it because bit takes me nearly an hour and I grudge the extra time when I am doing a boiler repair on a fixed charge basis.

Tony